1. Field of the Invention
The present invention relates to a method for manufacturing a composite substrate having a silicon thin film on a pyrolytic boron nitride substrate.
2. Description of the Related Art
A pyrolytic boron nitride (PBN) is a boron nitride produced by a CVD method, and it is a ceramics material having excellent features such as a high purity, high heat resistance, high insulation properties, high thermal shock resistance, chemical stability, and others. The PBN is extensively used in, e.g., a component in a heat treatment furnace or a cell used in an MBE method while utilizing such features of the PBN. However, the PBN material has the feature of chemical stability, whereas a surface of this material does not get wet with respect to almost all metals even at a high temperature and reactivity of the PBN material with respect to other materials is poor. Further, it has a drawback that interlayer delamination is apt to occur because the PBN material has a layer structure. Therefore, the PBN material has a problem that metallizing a surface thereof is very difficult and its use applications are limited.
In view of this problem, it is an object of the present invention to improve wettability of a surface of a PBN material with respect to a metal and expands use applications of the PBN material.